JPH06149458A - Ultrasonic information device - Google Patents

Abstract

PURPOSE:To provide the ultrasonic information device in which information is inputted and displayed by touching the surface of a substrate, which is equipped with an ultrasonic transmitting/receiving means and a display screen, with an input pen. CONSTITUTION:When an electric signal is inputted from an interdigital electrode T1, the electric signal is converted to a surface acoustic wave(SAW) and propagated through a glass substrate 11. Among the SAWs propagated through the glass substrate 11, only the SAWs at a central frequency and the adjacent frequency shown by interdigital electrodes R11-R14 are converted to electric signals and outputted from the interdigital electrodes R11-R14. When the propagating path of SAWs is touched with any material softer than the glass substrate 11 and easy to absorb ultrasonic waves, the SAW corresponding to the touched position is attenuated. On the display screen, the information is displayed corresponding to the touched part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention inputs information by touching the plate surface of a substrate provided with ultrasonic wave transmitting / receiving means with an input pen, and the information is displayed on a display screen provided on the other plate surface of the substrate. The present invention relates to an ultrasonic information device for displaying.

[0002]

2. Description of the Related Art In a conventional information device such as a personal computer and an electronic notebook, a keyboard is mainly used as an input means.
The input operation by the keyboard is complicated and time-consuming, and there are many mistakes in the operation, which is a big obstacle for beginners. Further, conventional personal computers and electronic organizers are generally large in size because the keyboard part and the display part are independent.

A transparent electrode type and an optical touch panel are mainly used for a pen input computer capable of inputting characters, symbols and other information directly on a panel. These touch panels have workability,
It has problems such as durability, sensitivity, etc., malfunction due to influence of surrounding environment such as light, and difficulty in displaying high-density information on the panel. In addition to a pen input computer, an electronic notebook and the like can be realized by applying a touch panel. Other than the above, the conventional touch panel mainly includes a method using a resistance film and a method using ultrasonic waves. The method using a resistance film is such that the resistance value of the transparent conductive film changes by touching the transparent conductive film (resistive film), and although the power consumption is low, the response time, sensitivity, durability, etc. Have problems in terms. In the method using ultrasonic waves, the surface acoustic wave is attenuated by touching a non-piezoelectric substrate on which the surface acoustic wave is excited in advance. As a conventional method of exciting a surface acoustic wave on a non-piezoelectric substrate, there are a method of indirectly exciting a wedge-shaped transducer using a bulk wave oscillator and a method of directly exciting a piezoelectric thin film transducer. The wedge-shaped transducer is used for non-destructive inspection by ultrasonic waves, etc., but is used only in a relatively low frequency region due to the problem of the working accuracy of the wedge angle. The piezoelectric thin film transducer is a method in which a piezoelectric thin film such as ZnO is vapor-deposited on a substrate to excite surface acoustic waves by interdigital electrodes, and since it has various transmission characteristics due to the interdigital electrode configuration, it is used as a high frequency device.
It is limited to the HF and VHF bands and has problems in workability and mass productivity. Thus, the response time in the traditional method is
There are problems in sensitivity, durability, work precision, workability, mass productivity, etc., and the frequency range used is also limited.

[0004]

An object of the present invention is to obtain high-density information which is excellent in workability, durability, and mass productivity, has low power consumption and is driven at a low voltage, and is sensitive to a panel by touching it. An object of the present invention is to provide an information device that can be input and can display information on the panel, is small and lightweight, is thin, convenient to carry, and easy to operate the panel.

[0005]

An ultrasonic wave according to claim 1
The information device has at least two board surfaces Z1 on one side of the board.
The other plate surface Z2 of the substrate is provided with ultrasonic wave transmitting / receiving means.
Equipped with information input means with display screen and information storage means
An ultrasonic information device comprising the information processing means
The information input means places the pen tip of the input pen on the plate surface Z1.
Including means for entering information by contacting,
The information processing means is the plate contacted by the pen tip.
Means for identifying a contacted portion on the surface Z1 and the contacted portion
At the position of the contacted part specified by the touched part specifying means
Based on the information input by the information input means
Force information detecting means, and the ultrasonic wave transmitting / receiving means is N sets.
Interdigital electrode P_i(I = 1, 2, ..., N)
Interdigital transducer P_iN interdigital corresponding to each
Pole group Q_i(I = 1, 2, ..., N) and
Interdigital electrode group Q_iEach has at least two pairs of blinds
Electrode Q_i-1And Q_i-2And the interdigital electrode P_i
The electrical signal of a frequency approximately corresponding to the electrode cycle length of
Sag electrode P_iInput to, and is approximately equal to the electrode period length
Means for exciting a surface acoustic wave having a wavelength on the plate surface Z1
And the wavelength of the surface acoustic wave excited on the plate surface Z1
Then the above-mentioned interdigital electrode Q_{i- 1}And Q_i-2Telegraph appearing in
And a means for outputting a signal is provided.
The interdigital transducer P in the wave receiving means_iAnd the above-mentioned comb shape
Electrode group Q_iThe surface acoustic wave propagation path between
The interdigital transducer P in the sound wave transmitting / receiving means_iAnd the above
Sagittal electrode group Q_iAnd the surface acoustic wave propagation path between
Is orthogonal to The contacted portion identifying means is the plate surface.
The contacted portion in the propagation path of the surface acoustic wave on Z1
The interdigital electrode Q_i-1And Q_i-2Out of
The interdigital electrode in which the magnitude of the electric signal is changed
Q_i-1Or Q_i-2It is characterized by specifying from the position of
It

In the ultrasonic information apparatus according to a second aspect of the present invention, the information storage means stores in advance a table in which the position of the plate surface Z1 is an address and the information associated with the position is data. The input information detecting means inputs the position of the contacted portion specified by the contacted portion specifying means as the address by the information storing means, and the data read from the address is input by the information inputting means. It is characterized by being information.

In the ultrasonic information apparatus according to a third aspect of the present invention, the information storage means stores a pattern of characters or symbols in advance, and the input information detection means specifies the contacted portion specifying means. A feature is that the locus formed by the movement of the position of the contacted portion is compared with the pattern read from the information storage unit, and the information input by the information input unit is detected by a pattern matching method. To do.

In the ultrasonic information apparatus according to a fourth aspect, the position of the contacted portion specified by the contacted portion specifying means by the input information detecting means is the information input by the information inputting means. It is characterized by

The ultrasonic information apparatus according to claim 5 includes means for causing the information processing means to display the information detected by the input information detecting means on the display screen for a predetermined time. And

According to another aspect of the ultrasonic information apparatus of the present invention, the information is displayed in at least two kinds of colors, and an electric signal of at least two kinds of frequencies which substantially corresponds to the electrode cycle length of the interdigital transducer P _i is displayed. Means are provided for exciting at least two kinds of surface acoustic waves having wavelengths substantially equal to the electrode period length to the plate surface Z1 by inputting to the interdigital transducer P _i , and the frequency and the color of the information. It is characterized in that means for associating with and is provided.

In the ultrasonic information apparatus according to a seventh aspect of the present invention, there are at least _two electrode cycle lengths L1 and L2 in the interdigital transducers P _i , Q _i-1 and Q _{i- 2} .
The electrode cycle length L1 or L2 is added to the interdigital electrode P _i.
Input an electric signal of a frequency almost corresponding to
1 is provided with means for exciting a surface acoustic wave having a wavelength substantially equal to the electrode period length L1 or L2.

In the ultrasonic information device according to the present invention, the output terminals of the interdigital transducer Q _i-1 are electrically connected to each other at a connection point N1, and the interdigital transducer Q _i is connected.
The respective output ends of _i-2 are electrically connected to each other at a connection point N2, and the means for inputting an electric signal to the interdigital electrode P _i has an output end connected to the input end of the interdigital electrode P _i. N switches S _i (i = 1, 1,
2, ..., N) and switch control means for sequentially electrically connecting and disconnecting the switches S _i at a predetermined cycle, and the pen is provided in a part of the propagation path of the surface acoustic wave on the plate surface Z1. It is characterized in that the contact with the tip is sensed from the magnitudes of the electric signals appearing at the connection point N1 and the connection point N2.

The ultrasonic information apparatus according to claim 9 is
Switch S_iEach input end of is electrically connected to each other
Connected at the point NS, the connection point N1 is connected via an amplifier
Electrically connected to the connection point NS, The interdigital electrode P
_iTo the above-mentioned interdigital electrode Q_i-1Consisting of the substrate between
Surface acoustic wave propagation path D_i(I = 1, 2, ..., N) is delayed
Oscillator H as an extension element_i(I = 1, 2, ..., N)
The oscillator H_iSignal loop of the above
Striped electrode P_iAnd the propagation path D_iAnd the interdigital electrode Q
_i-1And the amplifier.

According to a tenth aspect of the present invention, in the ultrasonic information device, the substrate is made of a substantially transparent piezoelectric ceramic, and the polarization axis of the piezoelectric ceramic is parallel to the thickness direction of the piezoelectric ceramic. The electrode P _i and the group of interdigital electrodes Q _i are provided on the plate surface Z1.

In the ultrasonic information apparatus according to claim 11, the substrate is made of a non-piezoelectric material, the ultrasonic wave transmitting / receiving means is made of ultrasonic devices A and B, and the ultrasonic device A is a piezoelectric thin plate a. The interdigital transducer P _i is provided, and the ultrasonic device B includes the interdigital transducer group Q on the piezoelectric thin plate b.
_i is provided, and the piezoelectric thin plates a and b are the plate surface Z
1 is provided.

In the ultrasonic information apparatus according to the twelfth aspect, the thickness of the piezoelectric thin plate a is equal to or less than the electrode period length of the interdigital transducer P _i , and the thickness of the piezoelectric thin plate b is the interdigital transducer Q. _{i −1} and Q _i−2 are less than or equal to the electrode period length, and the electrode period lengths of the interdigital electrodes P _i , Q _i−1, and Q _i−2 are elastic surfaces of a first-order mode or a second-order mode or higher. It is characterized in that it is substantially equal to the wavelength of the wave, and the phase velocity of the surface acoustic wave in the first mode or the second or higher modes is substantially equal to the propagation velocity of the surface acoustic wave excited in the single substrate.

The ultrasonic information apparatus according to claim 13 is characterized in that the piezoelectric thin plate a or b is made of piezoelectric ceramic, and the direction of the polarization axis of the piezoelectric ceramic is parallel to the thickness direction of the piezoelectric ceramic. And

An ultrasonic information device according to a fourteenth aspect is characterized in that the piezoelectric thin plate a or b is made of a polymer piezoelectric film such as PVDF.

The ultrasonic information device according to the fifteenth aspect is characterized in that the piezoelectric thin plate a or b is fixed to the plate surface Z1 through the plate surface on which the interdigital electrode is provided. And

[0020]

The ultrasonic information device of the present invention is provided with one plate surface Z of the substrate.
1 has at least two ultrasonic wave transmitting / receiving means and has a simple structure including an information input means having a display screen on the other plate surface Z2 of the substrate and an information processing means having an information storage means. The device can be made smaller, lighter and thinner. The ultrasonic wave transmitting / receiving means is composed of N sets of interdigital electrodes P _i (i
, 1, 2, ..., N) and N sets of interdigital electrode groups Q _i (i = 1, 2, ...) Corresponding to the interdigital electrode P _i , respectively.
, N), and each of the interdigital electrode groups Q _i has at least two sets of interdigital electrodes Q _i-1 (i = 1, 2, ...).
, N) and Q _{i -2} (i = 1, 2, ..., N). By adopting the structure in which the interdigital electrode P _i is used for input and the electric signal is input from the interdigital electrode P _i, it is possible to excite the surface acoustic wave on the plate surface Z1 of the substrate. Moreover, it is possible to efficiently generate surface acoustic waves on the plate surface Z with low power consumption and low voltage.
Can be excited to 1.

The interdigital electrodes Q _i-1 and Q _i-2 are used for output, and each of the interdigital electrodes Q _i-1 and Q _i-2 transmits / receives a surface acoustic wave to / from the interdigital electrode P _i . By adopting a structure in which the directional axes are arranged in common, the surface acoustic wave excited on the plate surface Z1 can be efficiently output as an electric signal. By contacting the propagation path of the surface acoustic wave on the plate surface Z1 (that is, between the interdigital electrodes P _i and Q _i-1 and between P _i and Q _i-2 ) with the pen tip of the input pen. Since the surface acoustic wave excited in Z1 disappears or attenuates, the interdigital transducers Q _i-1 and Q _i
The electric signal output to _i-2 also disappears or attenuates. In this way, it is detected that the pen tip is in contact with the propagation path of the surface acoustic wave on the plate surface Z1. Moreover, the ultrasonic information device of the present invention has a short response time and good sensitivity. It is necessary that the pen tip be made of a material that is softer than the substrate and that absorbs ultrasonic waves easily, and a human finger or the like also has the characteristic.
Further, it is possible to identify the contacted portion touched by the pen tip by discriminating the interdigital electrode among the interdigital electrodes Q _i-1 and Q _{i-2 where} the output electric signal disappears or attenuates.

[0022] By employing at least one structure for inputting an electric signal of a frequency substantially corresponding to the interdigital periodicity of interdigital electrodes P _i to interdigital electrodes P _i, substantially to the electrode period length on the plate surface Z1 It is possible to excite at least one surface acoustic wave having an equal wavelength. Also, the plate surface Z
The surface acoustic wave excited by No. 1 can be output as an electric signal from the interdigital transducers Q _i-1 and Q _i-2 according to its wavelength.

A structure in which at least two ultrasonic wave transmitting / receiving means are provided on the plate surface Z1 is adopted, and moreover, an elastic surface between the interdigital electrode P _i and the interdigital electrode group Q _{i in} one ultrasonic wave transmitting / receiving means. By adopting a structure in which the wave propagation path and the surface acoustic wave propagation path between the interdigital transducer P _i and the interdigital transducer group Q _i in another ultrasonic wave transmitting / receiving means are orthogonal to each other, the plate surface The contacted portion in Z1 can be specified more delicately. As the number of ultrasonic wave transmitting / receiving means increases, more detailed identification becomes possible.

The output terminals of the interdigital transducer Q _i-1 are electrically connected to each other at a connection point N1, and the interdigital transducer Q _i is connected.
_By electrically connecting the respective output ends of _i-2 to each other at the connection point N2, it is possible to confirm that the pen tip comes into contact with a part of the propagation path of the surface acoustic wave on the plate surface Z1. It can be detected from the magnitude of the electric signal appearing at. Interdigital electrode P as a means for inputting an electrical signal to the _i, an output connected to the input terminal of the interdigital electrodes P _i N number of switches _{S i (i = 1,2, ......} ,
N) is provided and the switches S _i are electrically connected and disconnected sequentially at a predetermined cycle. In this way, electrical signals can be sequentially input to the interdigital electrodes P _i . Therefore, for example, among the propagation paths of the surface acoustic waves on the plate surface Z1 (that is, between the interdigital electrodes P _i and Q _i-1 and between P _i and Q _i-2 ), for example, the interdigital electrodes P ₁ and Q. _In the case of contact between _1-1 and ₁ , the delayed electric signal output to the connection point N1 is attenuated or disappears only when the electric signal is input to the interdigital transducer P ₁ . In this way, the contact position can be clearly specified.

By adopting a structure in which the respective input ends of the switches S _i are electrically connected to each other at the connection point NS, and the connection point N1 is electrically connected to the connection point NS via an amplifier, the interdigital electrode is formed. Plate surface Z1 between P _i and Q _i-1
The surface acoustic wave propagation path D _i (i = 1, 2, ...,
Oscillator H _i (i = 1, 2, ..., N) as a delay element
N) can be configured. The signal loop of the oscillator H _i includes the interdigital electrode P _i , the propagation path D _i, and the interdigital electrode Q.
_It consists of _i-1 and an amplifier. In this way, since the circuit configuration is simplified, it is possible to further reduce the size and weight of the device, and it is possible to drive at low voltage with low power consumption.

The interdigital electrodes P _i , Q _i-1 and Q _i-2 each have at least two electrode period lengths L1 and L.
By adopting the structure having 2, the interdigital electrode P
An electric signal having a frequency substantially corresponding to the electrode cycle length L1 or L2 can be input to _i . Therefore, a surface acoustic wave having a wavelength substantially equal to the electrode period length L1 or L2 can be excited on the plate surface Z1. Further, surface acoustic waves having a wavelength substantially equal to the electrode period length L1 or L2 excited on the plate surface Z1 can be output as electric signals from the interdigital electrodes Q _i-1 and Q _{i -2} . By arranging the interdigital electrode P _i and the interdigital electrode group Q _i in the ultrasonic wave transmitting / receiving means such that the electrode fingers having the smaller electrode cycle lengths are inside each other, that is, the inter-electrode distance is small, Attenuation of surface acoustic waves excited on the plate surface Z1 can be suppressed. This is to solve the problem that the smaller the electrode period length is, the higher the frequency of the surface acoustic wave is excited on the plate surface Z1, and the higher the frequency of the surface acoustic wave is, the more easily it is attenuated.

The ultrasonic information apparatus of the present invention includes, as information input means, means for inputting information by bringing the pen tip of the input pen into contact with the plate surface Z1. In addition, a structure is adopted in which information is displayed on the display screen by contact. The information on the display screen can be viewed as it is through the plate surface Z1. That is, a structure in which the display and the keyboard are integrated is adopted. Moreover, the transparency of the display screen seen through the plate surface Z1 is excellent. Therefore, further reduction in size, weight and thickness of the device is promoted, the screen is clear, and even a beginner can easily operate. In addition, the ultrasonic information device of the present invention employs a structure in which information corresponding to the position of the contacted portion is displayed on the display screen for a predetermined time. However, the information is information to be input from now on or information which is already stored and is output to the display screen based on the position of the contacted portion. Therefore, when entering information such as characters, use the pen tip
By drawing on 1, the character can be displayed on the display screen. By directly writing characters, symbols, and other information on the plate surface Z1 in this manner, not only the information can be input but also an image can be displayed on the display screen. Further, it is also possible to output the previously stored information to the display screen by touching a predetermined portion of the plate surface Z1.

In the ultrasonic information apparatus of the present invention, means for specifying the contacted portion on the plate surface Z1 contacted by the pen tip as information processing means and the position of the contacted portion specified by the contacted portion specifying means are provided. And input information detection means for detecting information input by the information input means. Further, the information processing means of the ultrasonic information device of the present invention comprises an information storage means. Plate surface Z1 as information storage means
By employing a structure in which a table in which the upper position is an address and the information associated with the position is data is stored in advance, the position of the contacted portion is input as the address. Therefore, the stored data can be read from that address. Further, by adopting a structure in which patterns such as characters and symbols are stored in advance as the information storage means, the locus formed by the movement of the position of the contacted portion is input, and the locus and the pattern are compared. And
The information indicated by the trajectory is recognized. Therefore, information such as characters drawn on the plate surface Z1 can be input.

By adopting a structure in which information is displayed in at least two kinds of colors as the display screen, and adopting a structure in which the frequency of the electric signal input to the interdigital transducer P _i corresponds to the color of the display screen. By switching the frequency to the same location on the display screen, it becomes possible to input information that is color-coded separately. That is, it is possible to input color-coded information for each frequency by touching the above-mentioned location on the plate surface Z1 for each frequency. Therefore, the amount of information to be input is also increased.

A transparent piezoelectric ceramic such as La-added zircon / lead titanate (PLZT) porcelain is used as the substrate, and the structure in which the polarization axis direction of the piezoelectric ceramic and the thickness direction are parallel to each other is adopted. As a result, surface acoustic waves can be efficiently excited on the substrate. At this time, the interdigital electrode P _i and the interdigital electrode group Q _i are directly provided on the substrate. Moreover, by adopting a substantially transparent structure as the piezoelectric ceramic, the information appearing on the display screen can be seen from the plate surface Z1. In order to propagate the surface acoustic wave to the plate surface Z1 of the substrate made of piezoelectric ceramic, the thickness of the substrate must be three times or more the electrode period length of the interdigital electrodes P _i , Q _i-1 and Q _i-2. Is desirable. When the thickness of the substrate is smaller than the electrode period length and is thin, the Lamb wave propagates, but if there is a mode that can function as a touch panel, the Lamb wave can also be used. As the substrate, a single crystal such as LiNbO ₃ , LiTaO ₃ or the like can be considered in addition to the piezoelectric ceramic. These single crystals are promising as substrates because they are transparent and have piezoelectricity, but because they have anisotropy as crystals, it is necessary to devise them at the design stage including the electromechanical coupling coefficient. And may require extra electronic circuitry as well. Among piezoelectric ceramics, PLZT is transparent and has piezoelectricity, workability,
It is a promising substrate because of its excellent durability. P
By utilizing the in-plane isotropy of the plate surface Z1 of the substrate made of LZT, the surface acoustic wave between the interdigital transducer P _i and the interdigital transducer group Q _{i in} one ultrasonic wave transmitting / receiving means is generated. The interdigital transducer P in the propagation path and another ultrasonic wave transmitting / receiving means
_{When the} structure in which the propagation path of the surface acoustic wave between _i and the interdigital electrode group Q _i is orthogonal to each other is adopted, the interdigital electrode group Q _i is output to one interdigital electrode group Q _i and the other interdigital electrode group Q _i. It is possible to make the levels of the electric signals to be substantially the same. Therefore, not only can the circuit structure be simplified, the device can be made smaller and lighter, and the device can be made thinner, but the output signals can be made uniform at all times, so that the signal processing is accurate and the sensitivity is improved. Furthermore, since the resolution is improved, the amount of information to be input can be increased.

The substrate is made of a non-piezoelectric material, and the ultrasonic wave transmitting / receiving means has a structure of ultrasonic devices A and B. The ultrasonic device A is a piezoelectric thin plate a and the interdigital electrodes P _i.
Since the ultrasonic device B is provided with the interdigital electrode group Q _i on the piezoelectric thin plate b, the ultrasonic device B has a primary mode or a secondary mode or higher on the plate surface Z1 of the substrate that is in contact with the interdigital electrode P _i . A surface acoustic wave of a mode can be excited. At this time, by adopting a structure in which the phase velocity of this surface acoustic wave is substantially equal to the propagation velocity of the surface acoustic wave in the substrate alone, the electric energy applied from the interdigital transducer P _i is converted into the surface acoustic wave. It is possible not only to increase the degree of vibration, but also to eliminate reflection and the like caused by mismatch of acoustic impedance at the interface between the piezoelectric thin plate and the substrate. In this way, surface acoustic waves can be efficiently excited on the plate surface Z1 of the substrate with low power consumption and without applying a high voltage. Moreover, since the area of the substrate can be made relatively large, a wide range of applications are possible. The piezoelectric thin plates a and b are provided on the plate surface Z1.

The thickness of each of the piezoelectric thin plates a and b in the ultrasonic devices A and B is set to be equal to or less than the electrode period length of the interdigital electrode, and the electrode period length of the interdigital electrode is elastic in the first mode or the second or higher modes. By adopting a structure that is approximately equal to the wavelength of the surface wave, it is possible not only to increase the degree of conversion of electric energy applied from the interdigital transducer into surface acoustic waves, but also to use piezoelectric thin plates and non-piezoelectric materials. It is possible to remove reflection and the like caused by mismatch of acoustic impedance at the interface with the substrate.
The smaller the electrode period length of the interdigital transducer, that is, the ratio (d / λ) of the thickness d of the piezoelectric thin plate to the wavelength λ of the surface acoustic wave, the greater the effect.

By adopting a structure in which piezoelectric ceramics are used as the piezoelectric thin plates a and b, and the direction of the polarization axis of the piezoelectric ceramics and the thickness direction are parallel to each other, it is possible to efficiently carry out the primary process on a substrate made of a non-piezoelectric material. It is possible to excite a surface acoustic wave of a mode or a second or higher order mode.

By using a polymer piezoelectric film such as PVDF as the piezoelectric thin plate, it is possible to efficiently excite the first-order mode or the second or higher-order mode surface acoustic waves on the substrate made of a non-piezoelectric material.

By adopting a structure in which the interdigital electrode is provided at the interface between the substrate made of a non-piezoelectric material and the piezoelectric thin plate, the electric energy applied to the interdigital electrode can be efficiently converted into a surface acoustic wave. .

The ultrasonic information apparatus of the present invention touches the plate surface Z1 with a dedicated input pen to instruct processing, recognize handwritten characters, input characters such as Kana-Kanji conversion, draw figures and pictures, insert line feeds and insert characters. Even beginners can easily perform operations such as deletion. An optional external keyboard can also be connected, allowing keyboard input. It can also support communication functions and can be connected to printers, external CRTs, etc.

[0037]

1 is a perspective view showing an embodiment of an ultrasonic information device of the present invention. The present embodiment comprises a touch panel unit 1, an information processing unit 2 (not shown in FIG. 1 because it is provided inside the main body), a power switch 3, a disc insertion chamber 4, an input pen storage chamber 5 and a cover 6. . An input pen is stored in the input pen storage chamber 5. At the time of use, the cover 6 is lifted as shown in FIG. When the power switch 3 is turned on, the operation procedure is sequentially displayed on the touch panel unit 1. Therefore, by touching the designated portion of the touch panel unit 1 with the input pen according to the instruction, information can be input or already saved. The displayed information can be displayed on the touch panel unit 1. In this way, by touching the touch panel unit 1, processing instructions, recognition of handwritten characters, character input such as kana-kanji conversion,
Even beginners can easily perform operations such as drawing of figures and pictures, line feed / insertion / deletion without a manual. When characters, symbols, and other information are written in the touch panel unit 1 by the input pen, the information is sent to the information processing unit 2 for processing and displayed on the touch panel 1. When storing the information in a predetermined disc, the disc is inserted into the disc insertion chamber 4.
An optional external keyboard can also be connected, allowing keyboard input. It also supports communication functions, and can be connected to a printer, external CRT, etc.

FIG. 2 is a plan view showing an embodiment of the touch panel unit 1. The touch panel unit 1 is an ultrasonic device 7,
8, 9, 10, glass substrate 11 and display screen 12 (not shown in FIG. 2). The ultrasonic device 7 comprises a piezoelectric ceramic thin plate 13 provided with interdigital electrodes T1 and T2. The ultrasonic device 8 comprises a piezoelectric ceramic thin plate 13 provided with interdigital electrodes T3 and T4. The ultrasonic device 9 includes comb-shaped electrodes R11, R12, R13, R1 on the piezoelectric ceramic thin plate 13.
4, R21, R22, R23 and R24 are provided. The ultrasonic device 10 includes a piezoelectric ceramic thin plate 13, a comb-shaped electrode R31,
R32, R33, R34, R41, R42, R43 and R44 are provided. The piezoelectric ceramic thin plate 13 is made of TDK 101A material (product name) having a thickness of 230 μm. Each of the interdigital electrodes is made of an aluminum thin film. The glass substrate 11 is 70 m long
It is made of Pyrex glass with m, width 55 mm, and thickness 1.9 mm. The piezoelectric ceramic thin plate 13 is provided on the glass substrate 11. The display screen 12 is provided on the other plate surface of the glass substrate 13. The piezoelectric ceramic thin plate 13 has a thickness of about 20.
It is fixed on the glass substrate 11 with an epoxy resin of μm. Each of the interdigital electrodes has an electrode cycle length of 840.
It is a normal type having 7.5 pairs of electrode fingers in μm.
When the touch panel unit 1 is mounted on the ultrasonic information apparatus of FIG. 1, the touch panel unit 1 is mounted with the plate surface of each ultrasonic device facing outward, and It is mounted so that only the area surrounded by each ultrasonic device is exposed to the outside.

FIG. 3 is a plan view showing the ultrasonic devices 7 and 9 in the touch panel section 1 of FIG. The ultrasonic devices 7 and 9 face each other. The relationship between the ultrasonic devices 8 and 10 is similar to the relationship between the ultrasonic devices 7 and 9. The interdigital electrodes T1, T2, T3 and T4 are used for input and have an electrode crossing width of 18 mm. Interdigital electrodes R11 to R14, R21 to R24, R31 to R34 and R
41 to R44 are used for output and the electrode crossing width is 2.7.
mm. The interdigital electrodes R11 to R14 are interdigital electrodes T
Corresponding to 1, the interdigital electrodes R21 to R24 are interdigital electrodes T2.
Corresponding to, the interdigital electrodes R31 to R34 are interdigital electrodes T3.
Corresponding to, the interdigital electrodes R41 to R44 are interdigital electrodes T4.
It corresponds to.

FIG. 4 is a sectional view of the touch panel portion 1 of FIG. 2, showing the relationship between the input ultrasonic device and the output ultrasonic device. The interdigital transducer for input and the interdigital transducer for output are provided on the glass substrate 11 side of the piezoelectric ceramic thin plate 13.

FIG. 5 is a plan view showing an embodiment of a comb-shaped electrode used in place of the comb-shaped electrode used in the touch panel portion 1 of FIG. This interdigital electrode is a normal type which is composed of 5 pairs of electrode fingers having an electrode cycle length of 620 μm and 5 pairs of electrode fingers having an electrode cycle length of 295 μm. When used, the electrode fingers having an electrode period length of 295 μm are arranged inside each other. This is because in consideration of the fact that the shorter the electrode period length is, the higher the surface acoustic wave is excited on the glass substrate 11, and the higher the surface acoustic wave is, the more easily it is attenuated. In this way, the smaller the electrode cycle length, the smaller the propagation path length of the surface acoustic wave (that is, the distance between the electrodes).

FIG. 6 is a block diagram showing a case where the touch panel unit 1 of the ultrasonic information apparatus of FIG. 1 is driven by using an rf pulse. FIG. 7 is a waveform diagram in each part of the configuration diagram of FIG. When the touch panel unit 1 is driven, the continuous wave generated by the signal generator is generated by the double balanced mixer (DBM) 1 and D.M. B. M.
2 modulated into rf pulses -1 and -2. D.
B. M. 1 and D.I. B. M. 2 plays a role of switching, and the interdigital electrodes T1 and T3 (hereinafter T1)
Rf pulse to the group) or to the interdigital electrodes T2 and T4 (hereinafter referred to as the T2 group).
The f pulse is applied. When the rf pulse is applied to the interdigital transducer of the T1 group, only the rf pulse having a frequency substantially corresponding to the electrode period length of the interdigital transducer of the T1 group is converted into a surface acoustic wave and the input ultrasonic device 7 and 8 propagates through the piezoelectric ceramic thin plate 13 and further propagates through the glass substrate 11. Of the surface acoustic waves propagating through the glass substrate 11, the interdigital electrodes R11 to R14 of the output ultrasonic device 9 and the interdigital electrodes R31 to R34 of the output ultrasonic device 10 have a wavelength substantially equal to the electrode cycle length. Only surface acoustic waves are converted into delayed electric signals and output from the interdigital transducers R11 to R14 and R31 to R34 (hereinafter referred to as R1 group). R for T2 group interdigital transducer
When the f pulse is applied, only the rf pulse having a frequency substantially corresponding to the electrode period length of the T2 group interdigital transducer is converted into a surface acoustic wave and the input ultrasonic device 7
And 8 propagate through the piezoelectric ceramic thin plate 13 and further propagate through the glass substrate 11. Of the surface acoustic waves propagating through the glass substrate 11, the interdigital transducer R of the output ultrasonic device 9
21-R24 and the interdigital electrodes R41-R44 of the output ultrasonic device 10, only surface acoustic waves having wavelengths substantially equal to the electrode cycle lengths are converted into delayed electrical signals to form the interdigital electrode R.
21-R24 and R41-R44 (hereafter called R2 group)
Is output from. In this manner, the delayed electric signals are input to the R1 group and the R2 group by alternately inputting the electric signals to the interdigital electrodes of the T1 group and the T2 group.
It is possible to alternately output to the interdigital electrodes of the group. Interdigital electrodes R11 and R21, R12 and R22, R13 and R2
3, R14 and R24, R31 and R41, R32 and R42, R33 and R4
Not only does the circuit structure be simplified by connecting 3, and R34 and R44, respectively, but also two sets of interdigital electrodes R11 and R21, R12 and R22, R13 and R23, R14 and R24,
R31 and R41, R32 and R42, R33 and R43, and R34 and R
Forty-four delayed electrical signals are received in duplicate. Therefore, when the propagation path of the surface acoustic wave propagating through the glass substrate 11 is contacted with a material that is softer than the glass substrate 11 and easily absorbs ultrasonic waves when an electric signal is input to the interdigital electrodes of the T1 group, the T1 group The surface wave corresponding to the contact position is attenuated only when an electric signal is input to the interdigital transducer. Similarly, when the propagation path of the surface acoustic wave propagating to the glass substrate 11 is contacted when an electric signal is input to the interdigital transducer of the T2 group,
The surface wave corresponding to the contact position is attenuated only when an electric signal is input to the T2 group interdigital transducer. Such delayed signals and are amplified and rectified to become DC signals and, respectively. By setting an appropriate threshold voltage value between the DC voltage values corresponding to the case where the glass substrate 5 is contacted and the case where the glass substrate 5 is not contacted, a digital signal is obtained in the comparator. This digital signal is taken into the computer as a parallel signal at an appropriate timing by the computer.

FIG. 8 is a block diagram showing a case where the touch panel unit 1 of the ultrasonic information apparatus shown in FIG. 1 is driven by forming a delay line oscillator. Waveform diagrams in each of the components in the configuration diagram of FIG. 8 are the same as those shown in FIG. 7. In FIG. 8, a first delay element is provided between the interdigital electrodes T1 and R11 or between T2 and R21, and a second delay element is provided between the interdigital electrodes T3 and R31 or between T4 and R41. A delay line oscillator having an 8-shaped signal loop is formed. When the touch panel unit 1 is driven, the switches 1, 2, 3 and 4 are operated by a command from the computer. Switch 1
Switches 2 and 4 (hereinafter referred to as S2 group) are open while switches 3 and 3 (hereinafter referred to as S1 group) are closed. In this way, by opening and closing the switches of the S1 group and the S2 group, the interdigital electrodes T
Electrical signals are alternately input to 1 and T3 (hereinafter referred to as T1 group) and interdigital electrodes T2 and T4 (hereinafter referred to as T2 group). The electrical signal input to the T1 group or the T2 group is modulated into rf pulses -1 and -2 by clock pulse -1 or -2 from the computer, respectively. When the switch of the S1 group is closed and the electric signal -1 is input to the interdigital electrode of the T1 group, only the electric signal having a frequency substantially corresponding to the electrode period length of the interdigital electrode of the T1 group is converted into a surface acoustic wave. Is propagated through the piezoelectric ceramic thin plate 13 of the input ultrasonic devices 7 and 8, and the glass substrate 1
Propagate 1. Of the surface acoustic waves propagating through the glass substrate 11, the interdigital transducer R11 of the output ultrasonic device 9
R14 and the interdigital transducer R of the output ultrasonic device 10
Only surface acoustic waves having wavelengths substantially equal to the electrode period lengths of 31 to R34 are converted into delayed electric signals and the interdigital electrodes R11 to R14.
And R31 to R34 (hereinafter referred to as R1 group). When the switch of the S2 group is closed and the electric signal -2 is input to the interdigital transducer of the T2 group, T2
Only electric signals having a frequency substantially corresponding to the electrode period length of the interdigital transducers of the group are converted into surface acoustic waves and propagated through the piezoelectric ceramic thin plate 13 of the input ultrasonic devices 7 and 8, and further propagated through the glass substrate 11. To do. Glass substrate 1
1 of the surface acoustic waves propagating in 1 of the interdigital transducers R21 to R24 of the output ultrasonic device 9 and the interdigital electrodes R41 to R44 of the output ultrasonic device 10 having a wavelength substantially equal to the electrode period length. Only the interdigital electrodes R21 to R24 and R41 to R44 (hereinafter R2) are converted into delayed electric signals.
(Called a group). In this way, T
By alternately inputting electric signals to the interdigital electrodes of the 1st group and the T2 group, delayed electric signals can be output alternately to the interdigital electrodes of the R1 group and the R2 group. Interdigital electrodes R11 and R21, R12 and R
22, R13 and R23, R14 and R24, R31 and R41, R32 and R4
2, R33 and R43, and R34 and R44, respectively, not only simplifies the circuit structure, but also each of the two sets of interdigital electrodes R11 and R21, R12 and R22, R13 and R23,
The delayed electrical signals of R14 and R24, R31 and R41, R32 and R42, R33 and R43, and R34 and R44 are received in an overlapped form. However, a part of the electric signals output from the interdigital electrodes R11 and R21 and a part of the electric signals output from the interdigital electrodes R31 and R41 of the two sets of the interdigital electrodes are respectively amplified by the amplifier A and the amplifier. After being amplified by B and controlled to a predetermined phase by each phase shifter, it is input again to the interdigital electrodes of the T1 group and the T2 group via the switches of the S1 group and the S2 group. That is, the electric signal input to the interdigital transducer T1 or T2 via the switch 1 or 2 is input to the interdigital transducer T3 or T4 after passing through the amplifier A and then the switch 3 or 4. Further, the electric signal input to the interdigital transducer T3 or T4 via the switch 3 or 4 is input to the interdigital transducer T1 or T2 via the switch 1 or 2 after passing through the amplifier B. In this way, a delay line oscillator having an 8-shaped signal loop is formed. By the way, two pairs of each of the interdigital transducers R11, R21, and R12 are provided.
And R22, R13 and R23, R14 and R24, R31 and R41, R32 and R42, R33 and R43, and R34 and R44 are attenuated (or) by contacting the glass substrate 11. The propagation path of the surface acoustic wave propagating through the glass substrate 1 when an electric signal is input to the interdigital transducers of the T1 group (between the interdigital transducers T1 and R11 to R14 and the interdigital transducers T3 and R31 to R34). If a material that is softer than the glass substrate 11 and easily absorbs ultrasonic waves is contacted with (between) the surface wave corresponding to the contact position is attenuated only when an electric signal is input to the interdigital transducer of the T1 group. Similarly, when an electric signal is input to the interdigital transducer of the T2 group, the glass substrate 11
Propagation path of surface acoustic waves propagating in the space (interdigital electrodes T2 and R2
Contact between 1 to R24 and between the interdigital electrodes T4 and R41 to R44), the surface wave corresponding to the contact position is attenuated only when an electric signal is input to the interdigital electrodes of the T2 group. To do. Such delayed signals and are amplified and rectified to become DC signals and, respectively. By setting an appropriate threshold voltage value between the DC voltage values corresponding to the case where the glass substrate 11 is contacted and the case where the glass substrate 11 is not contacted, a digital signal is obtained in the comparator. This digital signal is taken into the computer as a parallel signal at an appropriate timing by the computer. This delay line oscillator driving method does not require a pulse generator, so r shown in FIG.
The device can be further downsized, the power consumption can be reduced, and the voltage can be reduced as compared with the case of driving using the f pulse.

When the ultrasonic information device of FIG. 1 is driven, color-coded information corresponding to the contact position appears on the display screen 7 of the display device according to a command from the computer. Moreover, a system is incorporated in which the frequency of the electric signal input to the interdigital electrodes of the T1 group or the T2 group corresponds to the color thereof. The information on the display screen 7 can be viewed through the glass substrate 5. In this way, when the propagation path of the surface acoustic wave propagating through the glass substrate 5 is contacted, the surface acoustic wave propagating along the propagation path is attenuated or disappears, and accordingly, the display screen 7 corresponds to the contact position. Then, color-coded information appears. Moreover, by performing an operation of switching the frequency of the input electric signal, the glass substrate 5 at the same position is brought into contact with the display screen 7 to input information in a plurality of colors corresponding to the type of frequency at the same position. It becomes possible to do. That is, if two kinds of frequencies are used, it is possible to input information that is color-coded with two kinds of colors at the same position. In addition, a system is built in which the information corresponding to the contact position is displayed on the display screen for a predetermined time. In this way, for example, when a character or the like is drawn on the glass substrate 5 with a substance that is softer than the glass substrate 5 and easily absorbs ultrasonic waves, the character can be displayed on the display screen 7. In the ultrasonic information device of FIG. 1, FIG.
When the interdigital transducer is used, there are two types of electrode cycle lengths of the interdigital transducer and the difference between the respective values is large. Therefore, the frequencies of the two types of electric signals input to the interdigital transducer are set. The difference between the values of can be increased. Moreover, since the frequencies of the electric signals to be input can be further subdivided into several types in correspondence with the electrode period lengths of the respective types, as a result, the types of frequencies of the electric signals to be input can be further increased.

9 and 10 show interdigital electrodes T1 and R1.
It is a characteristic view which shows the relationship of the insertion loss with respect to the frequency between 1. However, FIG. 9 shows the case where the glass substrate 11 is not touched, and FIG. 10 shows the case where the glass substrate 11 is touched. The peak near 3.96 MHz corresponds to the surface acoustic wave of the first mode. Focusing on the surface acoustic wave of the first-order mode, it can be seen that the difference in insertion loss between contact and non-contact is about 10 dB. This change in insertion loss is a sufficient change for signal processing of the touch panel unit 1.

11 and 12 show r of 3.96 MHz.
It is a figure which shows the response characteristic between the interdigital transducers T1 and R11 when f pulse is applied. However, FIG. 11 shows the case where the glass substrate 11 is not in contact, and FIG.
1 shows the case of contact on the top. Since the glass substrate 11 is provided between the interdigital electrodes T1 and R11, it can be seen that good response characteristics are exhibited with no electromagnetic direct waves and little spurious. Therefore, signal processing can be facilitated.

FIG. 13 is a characteristic diagram showing an oscillation spectrum in the delay line oscillator shown in FIG. However, this is when the frequency of the input electric signal is f1. fo represents the fundamental wave and is 3.951 MHz. Touch panel 1
Since it is designed in the first-order mode, stable oscillation is obtained without being affected by other modes. Further, since the surface wave propagates with almost no spread, it can be easily oscillated without being affected by other waves.

FIG. 14 shows the glass substrate 1 of the touch panel section 1.
2 is a characteristic diagram showing a velocity dispersion curve of a surface acoustic wave propagating in FIG. 1, where the wave number k of the surface acoustic wave and the thickness d of the piezoelectric ceramic thin plate 13 are formed.
It is a figure which shows the phase velocity of each mode with respect to the product (kd) or the ratio of d with respect to the wavelength (lambda) of surface acoustic wave (d / (lambda)). However, the piezoelectric ceramic thin plate 13 has a plate surface (a glass side plate surface) of the piezoelectric ceramic thin plate 13 which is in contact with the glass substrate 11 (a glass side plate surface) which is in an electrically open state and which is in contact with one side of the plate (air side). The side plate surface) is electrically short-circuited, and the glass side plate surface and the air side plate surface of the piezoelectric ceramic thin plate 11 are both electrically short-circuited. In the present embodiment, the plate surface of the piezoelectric ceramic thin plate 11 is coated with a metal thin film to electrically short the plate surface. In this figure, "short" indicates a short-circuit state and "open" indicates an open state. Surface acoustic waves have multiple modes. The zero-order mode is the fundamental Rayleigh wave, and when the kd value is zero, the zero-order mode agrees with the Rayleigh wave velocity of the glass substrate 11 and converges to the Rayleigh wave velocity of the piezoelectric ceramic thin plate 13 as the kd value increases. ing. There is a cutoff frequency in the first and higher modes, and the kd values converge to the transverse wave velocity of the glass substrate 11 when the respective kd values are minimum. In this figure, the circles indicate measured values.

FIG. 15 shows the glass substrate 1 of the touch panel section 1.
FIG. 3 is a characteristic diagram showing a velocity dispersion curve of a surface acoustic wave propagating in 1 and showing a phase velocity of each mode with respect to a kd value or a d / λ value. However, in the piezoelectric ceramic thin plate 13, one in which both the glass side plate surface and the air side plate surface of the piezoelectric ceramic thin plate 13 are in an electrically open state and one in which the glass side plate surface of the piezoelectric ceramic thin plate 13 is in an electrically short-circuited state The air side plate surface was electrically open. In the zero-order mode, when the fd value is zero, it coincides with the Rayleigh wave velocity of the glass substrate 11 and converges to the Rayleigh wave velocity of the piezoelectric ceramic thin plate 13 as the kd value increases. There is a cutoff frequency in the first and higher modes, and the kd values converge to the transverse wave velocity of the glass substrate 11 when the respective kd values are minimum. In this figure, the circles indicate measured values.

FIG. 16 is a characteristic diagram showing the relationship between the effective electromechanical coupling coefficient k ² and the kd value calculated from the phase velocity difference of the piezoelectric ceramic thin plate 13 under two different electrical boundary conditions. However, the piezoelectric ceramic thin plate 13 uses a piezoelectric ceramic thin plate 13 on which a glass-side plate surface is provided with interdigital electrodes (IDT) to electrically short the air-side plate surface. The higher order mode k ² has a larger value than the zero order mode. Especially 1
In the next mode, the maximum value of k ² = 17.7% is shown when kd = 1.8.

FIG. 17 is a characteristic diagram showing the relationship between the effective electromechanical coupling coefficient k ² and the kd value calculated from the phase velocity difference of the piezoelectric ceramic thin plate 13 under two different electrical boundary conditions. However, the piezoelectric ceramic thin plate 13 uses a piezoelectric ceramic thin plate 13 on which a glass-side plate surface is provided with interdigital electrodes to electrically open the air-side plate surface. The higher order mode k ² has a larger value than the zero order mode.

FIG. 18 is a characteristic diagram showing the relationship between the effective electromechanical coupling coefficient k ² and the kd value calculated from the phase velocity difference of the piezoelectric ceramic thin plate 13 under two different electrical boundary conditions. However, as the piezoelectric ceramic thin plate 13, one in which the glass side plate surface of the piezoelectric ceramic thin plate 13 is electrically short-circuited and the interdigital electrode is provided on the air side plate surface is used.

FIG. 19 is a characteristic diagram showing the relationship between the effective electromechanical coupling coefficient k ² and the kd value calculated from the phase velocity difference of the piezoelectric ceramic thin plate 13 under two different electrical boundary conditions. However, as the piezoelectric ceramic thin plate 13, one in which the glass side plate surface of the piezoelectric ceramic thin plate 13 is electrically opened and an interdigital electrode is provided on the air side plate surface is used.

14 to 19, in the first and higher modes, k ² exhibits the maximum value when the velocity of the surface acoustic wave propagating through the touch panel portion 1 is equal to the velocity of the surface acoustic wave propagating through the glass substrate 11 alone. I understand.

16 to 19, in the structure in which the interdigital electrode is provided on the glass side plate surface of the piezoelectric ceramic thin plate 13 and the air side plate surface is electrically short-circuited, the electric energy applied to the interdigital electrode becomes a surface acoustic wave. It can be seen that the degree of conversion increases.

When a surface acoustic wave is excited on the glass substrate 11 of the touch panel portion 1, it is necessary to consider reflection and the like caused by acoustic impedance mismatch at the interface between the piezoelectric ceramic thin plate 13 and the glass substrate 11. As means for minimizing the reflection coefficient, the touch panel unit 1 is designed so that the surface wave velocity in the touch panel unit 1 and the surface wave velocity of the glass substrate 11 are equal, and the wavelength λ of the surface wave is set.
The touch panel unit 1 may be designed so that the ratio (d / λ) of the thickness d of the piezoelectric ceramic thin plate 13 with respect to is small. If d value is constant, it is 2 rather than 3rd order
The primary mode is more effective than the secondary and secondary modes.

[0057]

According to the ultrasonic information apparatus of the present invention, by adopting the structure in which the electric signal is inputted from the interdigital electrodes P _i (i = 1, 2, ..., N), the plate surface of the substrate is Surface acoustic waves can be excited in Z1. Moreover, surface acoustic waves can be efficiently excited with low power consumption and without applying a high voltage. Interdigital electrodes Q _i-1 and Q _i
-2 for output, and the interdigital electrodes Q _i-1 and Q _i-2
By adopting a structure in which the directional axes for transmitting and receiving the surface acoustic wave are common to the interdigital electrodes P _i , the surface acoustic wave excited on the plate surface Z1 can be efficiently used as an electric signal. Can be output. Board surface Z1
Propagation path of surface acoustic wave at (ie, interdigital electrode P
By contacting between _i and Q _i-1 and between P _i and Q _i-2 ) with the pen tip of the input pen, the surface acoustic wave excited on the plate surface Z1 disappears or attenuates. Interdigital transducer Q
_The electric signal output to _i-1 and Q _i-2 also disappears or attenuates. At this time, it is possible to identify the contacted portion touched by the pen tip by determining which _{one of} the interdigital electrodes Q _i-1 and Q _i-2 in which the output electric signal disappears or attenuates. In this way, the ultrasonic information device of the present invention has a short response time and good sensitivity. It is necessary that the pen tip be made of a material that is softer than the substrate and that absorbs ultrasonic waves easily, and a human finger or the like also has the characteristic.

[0058] By employing at least one structure for inputting an electric signal of a frequency substantially corresponding to the interdigital periodicity of interdigital electrodes P _i to interdigital electrodes P _i, substantially to the electrode period length on the plate surface Z1 It is possible to excite at least one surface acoustic wave having an equal wavelength. Also, the plate surface Z
The surface acoustic wave excited by No. 1 can be output as an electric signal from the interdigital transducers Q _i-1 and Q _i-2 according to its wavelength.

A structure in which at least two ultrasonic wave transmitting / receiving means are provided on the plate surface Z1 is adopted, and moreover, an elastic surface between the interdigital electrode P _i and the interdigital electrode group Q _{i in} one ultrasonic wave transmitting / receiving means. By adopting a structure in which the wave propagation path and the surface acoustic wave propagation path between the interdigital transducer P _i and the interdigital transducer group Q _i in another ultrasonic wave transmitting / receiving means are orthogonal to each other, the plate surface The contacted portion in Z1 can be specified more delicately. As the number of ultrasonic wave transmitting / receiving means increases, more detailed identification becomes possible.

The output terminals of the interdigital transducer Q _i-1 are electrically connected to each other at the connection point N1, and the interdigital transducer Q _i is connected.
_By electrically connecting the respective output terminals of _i-2 to each other at the connection point N2, the contacted portion on the plate surface Z1 can be detected from the magnitude of the electric signal appearing at the connection point N1 or the connection point N2. . As means for inputting an electrical signal to the interdigital electrodes P _i, of the N having an output connected to the input terminal of the interdigital electrodes P _i switch S _i (i =
1, 2, ..., N) and the structure in which the switches S _i are sequentially electrically interrupted at a predetermined cycle is used to sequentially input an electric signal to the interdigital transducer P _i. You can Therefore, when, for example, between the interdigital electrodes P ₁ and Q _{1-1 in} the propagation path of the surface acoustic wave on the plate surface Z1, the electrical signals are input to the interdigital electrode P ₁ . Only, the delayed electric signal output to the connection point N1 is attenuated or disappears. In this way, the contact position can be clearly specified.

By adopting a structure in which the respective input ends of the switches S _i are electrically connected to each other at the connection point NS and the connection point N1 is electrically connected to the connection point NS via an amplifier, the interdigital electrode is formed. Plate surface Z1 between P _i and Q _i-1
The surface acoustic wave propagation path D _i (i = 1, 2, ...,
Oscillator H _i (i = 1, 2, ..., N) as a delay element
N) can be configured. The signal loop of the oscillator H _i includes the interdigital electrode P _i , the propagation path D _i, and the interdigital electrode Q.
_It consists of _i-1 and an amplifier. In this way, since the circuit configuration is simplified, it is possible to further reduce the size and weight of the device, and it is possible to drive at low voltage with low power consumption.

The interdigital electrodes P _i , Q _i-1 and Q _i-2 each have at least two electrode period lengths L1 and L.
By adopting the structure having 2, the interdigital electrode P
An electric signal having a frequency substantially corresponding to the electrode cycle length L1 or L2 can be input to _i . Therefore, a surface acoustic wave having a wavelength substantially equal to the electrode period length L1 or L2 can be excited on the plate surface Z1. Further, surface acoustic waves having a wavelength substantially equal to the electrode period length L1 or L2 excited on the plate surface Z1 can be output as electric signals from the interdigital electrodes Q _i-1 and Q _{i -2} . By arranging the interdigital electrode P _i and the interdigital electrode group Q _i in the ultrasonic wave transmitting / receiving means such that the electrode fingers having the smaller electrode cycle lengths are inside each other, that is, the inter-electrode distance is small, Attenuation of surface acoustic waves excited on the plate surface Z1 can be suppressed.

As the information input means, means for inputting information by bringing the pen tip into contact with the plate surface Z1 is included. In addition, a structure is adopted in which information is displayed on the display screen by contact.
The information on the display screen can be viewed as it is through the plate surface Z1. Moreover, the transparency of the display screen seen through the plate surface Z1 is excellent. In other words, this is nothing but the structure in which the display and the keyboard are integrated. Therefore, further reduction in size, weight and thickness of the device is promoted, the screen is clear, and even a beginner can easily operate.

A structure is adopted in which information corresponding to the position of the contacted portion is displayed on the display screen for a predetermined time.
However, the information is information to be input from now on or information which is already stored and is output to the display screen based on the position of the contacted portion. Therefore, when inputting information such as a character, the character can be displayed on the display screen by drawing the character on the plate surface Z1 with a pen tip.
In this way, characters, symbols, and other information are printed on the plate surface Z1.
By directly writing in, it becomes possible not only to input such information but also to be displayed as an image on the display screen. Further, it is also possible to output the previously stored information to the display screen by touching a predetermined portion of the plate surface Z1.

As information processing means, means for specifying the contacted portion on the plate surface Z1 contacted by the pen tip, and input information detecting means for detecting the information input by the information input means based on the position of the contacted portion. Is included. Also,
The information processing means includes an information storage means. The position of the contacted portion is input as an address by adopting a structure in which a table in which the position on the plate surface Z1 is an address and the information associated with the position is data is previously stored as the information storage means. Therefore, the stored data can be read from that address. Further, by adopting a structure in which patterns such as characters and symbols are stored in advance as the information storage means, the locus formed by the movement of the position of the contacted portion is input, and the locus and the pattern are compared. Then, the information indicated by the trajectory is recognized. Therefore, information such as characters drawn on the plate surface Z1 can be input.

By adopting a structure in which information is displayed in at least two kinds of colors as the display screen, and adopting a structure in which the frequency of the electric signal input to the interdigital transducer P _i corresponds to the color of the display screen, By switching the frequency to the same location on the display screen, it becomes possible to input information that is color-coded separately. That is, it is possible to input color-coded information for each frequency by touching the above-mentioned location on the plate surface Z1 for each frequency. Therefore, the amount of information to be input is also increased.

A transparent piezoelectric ceramic such as La-doped zircon / lead titanate (PLZT) porcelain is used as the substrate, and a structure in which the polarization axis direction of the piezoelectric ceramic and the thickness direction are parallel to each other is adopted. As a result, surface acoustic waves can be efficiently excited on the substrate. At this time, the interdigital electrode P _i and the interdigital electrode group Q _i are directly provided on the substrate. Moreover, by adopting a substantially transparent structure as the piezoelectric ceramic, the information appearing on the display screen can be seen from the plate surface Z1. In order to propagate the surface acoustic wave to the plate surface Z1 of the substrate made of piezoelectric ceramic, the thickness of the substrate must be three times or more the electrode period length of the interdigital electrodes P _i , Q _i-1 and Q _i-2. Is desirable. When the thickness of the substrate is smaller than the electrode period length and is thin, the Lamb wave propagates, but if there is a mode that can function as a touch panel, the Lamb wave can also be used. As the substrate, a single crystal such as LiNbO ₃ , LiTaO ₃ or the like can be considered in addition to the piezoelectric ceramic. These single crystals are promising as substrates because they are transparent and have piezoelectricity, but because they have anisotropy as crystals, it is necessary to devise them at the design stage including the electromechanical coupling coefficient. And may require extra electronic circuitry as well. Among piezoelectric ceramics, PLZT is promising as a substrate because it is transparent and has excellent workability and durability. By utilizing the in-plane isotropy of the plate surface Z1 of the substrate made of PLZT, the interdigital transducer P in one ultrasonic wave transmitting / receiving means.
a propagation path of the surface acoustic wave between _i and the interdigital electrode group Q _i ,
In the case of adopting a structure in which the propagation path of the surface acoustic wave between the interdigital transducer P _i and the interdigital transducer group Q _{i in} another ultrasonic wave transmitting / receiving means is orthogonal to each other, one interdigital transducer group Q _i The level of the electric signal output to the other interdigital transducer group Q _i can be made substantially the same. Therefore, not only can the circuit structure be simplified and the device can be made smaller and lighter, but the output signals can be made uniform at all times, so that the signal processing is accurate and the sensitivity is improved. Furthermore, since the resolution is improved, the amount of information to be input can be increased.

The substrate is made of a non-piezoelectric material, and the ultrasonic wave transmitting / receiving means has a structure composed of ultrasonic devices A and B. The ultrasonic device A is a piezoelectric thin plate a and the interdigital transducer P _i.
Since the ultrasonic device B is provided with the interdigital electrode group Q _i on the piezoelectric thin plate b, the ultrasonic device B has a primary mode or a secondary mode or higher on the plate surface Z1 of the substrate that is in contact with the interdigital electrode P _i . A surface acoustic wave of a mode can be excited. At this time, by adopting a structure in which the phase velocity of this surface acoustic wave is substantially equal to the propagation velocity of the surface acoustic wave in the substrate alone, the electric energy applied from the interdigital transducer P _i is converted into the surface acoustic wave. It is possible not only to increase the degree of vibration, but also to eliminate reflection and the like caused by mismatch of acoustic impedance at the interface between the piezoelectric thin plate and the substrate. In this way, surface acoustic waves can be efficiently excited on the plate surface Z1 of the substrate with low power consumption and without applying a high voltage. Moreover, since the area of the substrate can be made relatively large, a wide range of applications are possible. The piezoelectric thin plates a and b are provided on the plate surface Z1.

The thickness of each of the piezoelectric thin plates a and b in the ultrasonic devices A and B is set to be equal to or less than the electrode period length of the interdigital transducer, and the electrode period length of the interdigital electrode is elastic in the first mode or the second or higher modes. By adopting a structure that is approximately equal to the wavelength of the surface wave, it is possible not only to increase the degree of conversion of electric energy applied from the interdigital transducer into surface acoustic waves, but also to use piezoelectric thin plates and non-piezoelectric materials. It is possible to remove reflection and the like caused by mismatch of acoustic impedance at the interface with the substrate.
The smaller the electrode period length of the interdigital transducer, that is, the ratio (d / λ) of the thickness d of the piezoelectric thin plate to the wavelength λ of the surface acoustic wave, the greater the effect.

Piezoelectric ceramics as the piezoelectric thin plate, PVDF
By adopting another polymer piezoelectric film, it is possible to efficiently excite the surface acoustic wave of the first-order mode or the second or higher order mode on the substrate. By adopting a structure in which the direction of the polarization axis of the piezoelectric ceramic coincides with the thickness direction, it is possible to efficiently excite the first-order mode or second-order or higher-order mode surface acoustic waves on the substrate.

By adopting a structure in which the interdigital electrodes are provided at the interface between the substrate made of a non-piezoelectric material and the piezoelectric thin plate, the electrical energy applied to the interdigital electrodes can be efficiently converted into surface acoustic waves. .

In this way, the ultrasonic information device of the present invention gives a processing instruction by touching the plate surface Z1 with the input pen.
Even beginners can easily perform handwriting recognition, character input such as kana-kanji conversion, drawing of figures and pictures, and line feed / insertion / deletion without a manual. An optional external keyboard can also be connected, allowing keyboard input. It also supports communication functions, and can be connected to a printer, external CRT, etc.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an ultrasonic information device of the present invention.

FIG. 2 is a plan view showing an embodiment of the touch panel unit 1.

3 is a plan view showing ultrasonic devices 7 and 9 in the touch panel unit 1 of FIG.

4 is a cross-sectional view of the touch panel unit 1 of FIG.

5 is a plan view showing an example of a comb-shaped electrode used in place of the comb-shaped electrode used in the touch panel unit 1 of FIG.

FIG. 6 shows the touch panel unit 1 of the ultrasonic information device of FIG.
The block diagram in the case of driving using f pulse.

FIG. 7 is a waveform diagram of each part of the configuration diagram of FIG.

8 is a configuration diagram when the touch panel unit 1 of the ultrasonic information apparatus of FIG. 1 is driven by forming a delay line oscillator.

FIG. 9 is a characteristic diagram showing the relationship between frequency and insertion loss between the interdigital transducers T1 and R11.

FIG. 10 is a characteristic diagram showing the relationship between the insertion loss and the frequency between the interdigital transducers T1 and R11.

FIG. 11 is a diagram showing response characteristics between the interdigital electrodes T1 and R11 when an rf pulse of 3.96 MHz is applied.

FIG. 12 is a diagram showing response characteristics between the interdigital electrodes T1 and R11 when an rf pulse of 3.96 MHz is applied.

13 is a characteristic diagram showing an oscillation spectrum in the delay line oscillator shown in FIG.

FIG. 14 is a characteristic diagram showing a velocity dispersion curve of a surface acoustic wave propagating through the glass substrate 11 of the touch panel unit 1.

FIG. 15 is a characteristic diagram showing a velocity dispersion curve of a surface acoustic wave propagating through the glass substrate 11 of the touch panel unit 1.

FIG. 16 is a characteristic diagram showing the relationship between the effective electromechanical coupling coefficient k ₂ and the kd value calculated from the phase velocity difference of the piezoelectric ceramic thin plate 13 under two different electrical boundary conditions.

FIG. 17 is a characteristic diagram showing the relationship between the effective electromechanical coupling coefficient k ₂ and the kd value calculated from the phase velocity difference of the piezoelectric ceramic thin plate 13 under two different electrical boundary conditions.

FIG. 18 is a characteristic diagram showing the relationship between the effective electromechanical coupling coefficient k ₂ and the kd value calculated from the phase velocity difference under two different electrical boundary conditions of the piezoelectric ceramic thin plate 13.

FIG. 19 is a characteristic diagram showing the relationship between the effective electromechanical coupling coefficient k ₂ and the kd value calculated from the phase velocity difference of the piezoelectric ceramic thin plate 13 under two different electrical boundary conditions.

[Explanation of symbols]

1 Touch Panel Section 2 Information Processing Section 3 Power Switch 4 Disk Insertion Room 5 Input Pen Storage Room 6 Cover 7, 8, 9, 10 Ultrasonic Device 11 Glass Substrate 12 Display Screen 13 Piezoelectric Ceramic Thin Plate T1, T2, T3, T4 Comb Electrodes R11, R12, R13, R14, R21, R22, R23, R24
Interdigital electrodes R31, R32, R33, R34, R41, R42, R43, R44
Interdigital electrode

Claims (15)

[Claims] 1. At least two on one plate surface Z1 of the substrate
The ultrasonic wave transmitting / receiving means
2 includes an information input means having a display screen and an information storage means.
It is an ultrasonic information device consisting of the information processing means provided.
Then, the information input means places the pen tip of the input pen on the plate surface Z1.
The information processing means includes means for inputting information by touching, and the information processing means
A means for identifying a contacted portion on the plate surface Z1;
Position of the contacted part specified by the contact part specifying means
The information input by the information input means is detected based on
Input information detection means, and the ultrasonic wave transmission / reception means includes N sets of interdigital electrodes P._i(I =
1, 2, ..., N) and the interdigital electrode P_iTo that
Corresponding N comb-shaped electrode group Q_i(I = 1, 2, ...
, N) and these interdigital electrode groups Q_iIs it
At least two comb-shaped electrodes Q each_i-1And Q_i-2so
Consists of the interdigital transducer P_iFrequency almost corresponding to the electrode cycle length of
A number of electrical signals to the interdigital electrode P_iEnter the above
The surface acoustic wave having a wavelength approximately equal to the pole period is applied to the plate.
A means for exciting the surface Z1 and a means for exciting the surface acoustic wave on the plate surface Z1.
The interdigital transducer Q_{i- 1}And Q_i-2Electrical signal that appears in
Means for outputting, and the interdigital electrode in one of the ultrasonic wave transmitting / receiving means.
P_iAnd the interdigital transducer group Q_iOf surface acoustic waves between and
Path and the interdigital transducer in another ultrasonic wave transmitting / receiving means.
Electrode P_iAnd the interdigital transducer group Q_iOf surface acoustic wave between
The propagation paths are orthogonal to each other,  The contacted portion identifying means is configured to apply the elasticity on the plate surface Z1.
The contacted portion in the propagation path of the surface wave is
Electrode Q_i-1And Q_i-2Out of the electrical signal
Of the interdigital transducer Q whose size changes_i-1Or Q_i-2
An ultrasonic information device characterized by being specified from the position of. 2. The information storage means stores in advance a table in which information is associated with the position on the plate surface Z1 as an address, and the input information detection means identifies the contacted portion. The position of the contacted portion specified by the means is input as the address by the information storage means, and the data read from the address is used as the information input by the information input means. 1. The ultrasonic information device according to 1. 3. The information storage means pre-stores patterns such as characters and symbols, and the input information detection means is formed by movement of the position of the contacted portion specified by the contacted portion specifying means. The ultrasonic information according to claim 1, characterized in that the information inputted by the information input means is detected by a pattern matching method by comparing the locus that is read with the pattern read from the information storage means. apparatus. 4. The input information detecting means uses the position of the contacted portion specified by the contacted portion specifying means as the information input by the information inputting means. Ultrasonic information device. 5. The information processing unit includes a unit for displaying the information detected by the input information detection unit on the display screen for a predetermined time. 4. The ultrasonic information device according to 4. 6. The information is displayed in at least two types of colors, and an electric signal having at least two types of frequencies substantially corresponding to the electrode period length of the interdigital electrodes P _i is applied to the interdigital electrodes P _i.
And means for exciting at least two kinds of surface acoustic waves having a wavelength substantially equal to the electrode period length to the plate surface Z1, and means for associating the frequency with the color of the information. The ultrasonic information device according to claim 1, 2, 3, 4 or 5, wherein the ultrasonic information device is provided. 7. The interdigital electrodes P _i , Q _i-1 and Q.
The electrode period length in _i-2 has at least two of L1 and L2, respectively, and the interdigital electrode P _i has the electrode period length L1 or L2.
Input an electric signal of a frequency almost corresponding to
The ultrasonic information according to claim 1, 2, 3, 4, 5 or 6, wherein means 1 is provided for exciting a surface acoustic wave having a wavelength substantially equal to the electrode period length L1 or L2. apparatus. 8. The output terminals of the interdigital transducer Q _i-1 are electrically connected to each other at a connection point N1, and the output terminals of the interdigital transducer Q _i-2 are electrically connected to each other. The means for inputting an electric signal to the interdigital transducer P _i , which is connected at the connection point N2, is composed of N switches S _i (i = i = n) whose output ends are connected to the input ends of the interdigital electrode P _i. 1, 2, ..., N),
Switch control means for electrically connecting and disconnecting the switches S _i sequentially and in a predetermined cycle, the connection of the contact of the pen tip to a part of the propagation path of the surface acoustic wave on the plate surface Z1 by the connection. 8. The ultrasonic information device according to claim 1, wherein detection is performed based on the magnitude of an electric signal appearing at the point N1 and the connection point N2. 9. The switch S_iEach input end of
Are electrically connected to each other at a connection point NS, and the connection point N1
Is electrically connected to the connection point NS via an amplifier,  The interdigital electrode P_iTo the above-mentioned interdigital electrode Q_i-1Leading to
Surface acoustic wave propagation path D consisting of the substrate between_i(I = 1,
Oscillator H using 2, ..., N) as a delay element_i(I = 1,
2, ..., N), the oscillator H_iSignal loop of the interdigital transducer P_iWhen,
The propagation path D_iAnd the interdigital electrode Q_i-1And the amplification
9. The ultrasonic wave according to claim 8, characterized by comprising:
Information device. 10. The substrate is made of a substantially transparent piezoelectric ceramic, and a direction of a polarization axis of the piezoelectric ceramic is parallel to a thickness direction of the piezoelectric ceramic, and the interdigital electrode P _i and the interdigital electrode group. The ultrasonic information device according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9, wherein Q _i is provided on the plate surface Z1. 11. The substrate is made of a non-piezoelectric material, the ultrasonic wave transmitting / receiving means is made of ultrasonic wave devices A and B, and the ultrasonic wave device A is formed by providing the interdigital electrode P _i on a piezoelectric thin plate a. The ultrasonic device B comprises a piezoelectric thin plate b provided with the interdigital electrode group Q _i , and the piezoelectric thin plates a and b are provided on the plate surface Z1. 3, 4, 5, 6,
7. The ultrasonic information device according to 7, 8 or 9. 12. The thickness of the piezoelectric thin plate a is not more than the electrode period length of the interdigital transducer P _i , and the thickness of the piezoelectric thin plate b is the electrode of the interdigital transducers Q _i-1 and Q _i-2 . The period length is equal to or less than the period length, and the electrode period length of the interdigital electrodes P _i , Q _i-1 and Q _i-2 is substantially equal to the wavelength of the surface acoustic wave in the first-order mode or in the second-order or higher modes. 12. The ultrasonic information device according to claim 11, wherein the phase velocity of the surface acoustic wave in the mode or in the second or higher modes is substantially equal to the propagation velocity of the surface acoustic wave excited in the single substrate. 13. The piezoelectric thin plate a or b is made of piezoelectric ceramic, and the direction of the polarization axis of the piezoelectric ceramic is parallel to the thickness direction of the piezoelectric ceramic. Ultrasonic information device. 14. The ultrasonic information device according to claim 11, wherein the piezoelectric thin plate a or b is made of a polymer piezoelectric film such as PVDF. 15. The piezoelectric thin plate a or b has the plate surface Z1 through the plate surface on which the interdigital electrode is provided.
It is fixedly attached to
13. The ultrasonic information device according to 13 or 14.